/*
 * @BEGIN LICENSE
 *
 * Psi4: an open-source quantum chemistry software package
 *
 * Copyright (c) 2007-2024 The Psi4 Developers.
 *
 * The copyrights for code used from other parties are included in
 * the corresponding files.
 *
 * This file is part of Psi4.
 *
 * Psi4 is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * Psi4 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with Psi4; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * @END LICENSE
 */

/* This code includes reference and correlation opdm contributions. */
#include "psi4/libtrans/integraltransform.h"
#include "psi4/libpsio/psio.hpp"
#include "psi4/libmints/matrix.h"
#include "occwave.h"
#include "defines.h"

namespace psi {
namespace occwave {

/*=======================*/
/*  tpdm_ref()           */
/*=======================*/
void OCCWave::tpdm_ref() {
    dpdbuf4 G;

    psio_->open(PSIF_OCC_DENSITY, PSIO_OPEN_OLD);

    if (reference_ == "RESTRICTED") {
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), 0,
                               "TPDM <OO|OO>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int kl = 0; kl < G.params->coltot[h]; ++kl) {
                    int k = G.params->colorb[h][kl][0];
                    int l = G.params->colorb[h][kl][1];
                    if (i == k && j == l) G.matrix[h][ij][kl] += 1.0;
                    if (i == l && j == k) G.matrix[h][ij][kl] -= 0.25;
                    if (i == j && k == l) G.matrix[h][ij][kl] -= 0.25;
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }

        global_dpd_->buf4_close(&G);

    }  // end RHF

    else if (reference_ == "UNRESTRICTED") {
        // Alpha-Alpha spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), 0,
                               "TPDM <OO|OO>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int kl = 0; kl < G.params->coltot[h]; ++kl) {
                    int k = G.params->colorb[h][kl][0];
                    int l = G.params->colorb[h][kl][1];
                    if (i == k && j == l) G.matrix[h][ij][kl] += 0.25;
                    if (i == l && j == k) G.matrix[h][ij][kl] -= 0.25;
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Beta-Beta spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[o,o]"), ID("[o,o]"), ID("[o,o]"), ID("[o,o]"), 0,
                               "TPDM <oo|oo>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int kl = 0; kl < G.params->coltot[h]; ++kl) {
                    int k = G.params->colorb[h][kl][0];
                    int l = G.params->colorb[h][kl][1];
                    if (i == k && j == l) G.matrix[h][ij][kl] += 0.25;
                    if (i == l && j == k) G.matrix[h][ij][kl] -= 0.25;
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Alpha-Beta spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,o]"), ID("[O,o]"), ID("[O,o]"), ID("[O,o]"), 0,
                               "TPDM <Oo|Oo>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int kl = 0; kl < G.params->coltot[h]; ++kl) {
                    int k = G.params->colorb[h][kl][0];
                    int l = G.params->colorb[h][kl][1];
                    if (i == k && j == l) G.matrix[h][ij][kl] += 0.25;
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

    }  // end UHF

    psio_->close(PSIF_OCC_DENSITY, 1);

}  // end of twopdm_ref

/*=======================*/
/*  tpdm_corr_opdm()     */
/*=======================*/
void OCCWave::tpdm_corr_opdm() {
    dpdbuf4 G;

    psio_->open(PSIF_OCC_DENSITY, PSIO_OPEN_OLD);

    if (reference_ == "RESTRICTED") {
        // TPDM <OO|OO>
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), 0,
                               "TPDM <OO|OO>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int kl = 0; kl < G.params->coltot[h]; ++kl) {
                    int k = G.params->colorb[h][kl][0];
                    int l = G.params->colorb[h][kl][1];

                    int hi = G.params->psym[i];
                    int hj = G.params->qsym[j];
                    int hk = G.params->rsym[k];
                    int hl = G.params->ssym[l];

                    int ii = i - G.params->poff[hi];
                    int jj = j - G.params->qoff[hj];
                    int kk = k - G.params->roff[hk];
                    int ll = l - G.params->soff[hl];

                    if (i == k && hj == hl) G.matrix[h][ij][kl] += 0.5 * gamma1corr->get(hj, jj, ll);
                    if (j == l && hi == hk) G.matrix[h][ij][kl] += 0.5 * gamma1corr->get(hi, ii, kk);
                    if (i == l && hj == hk) G.matrix[h][ij][kl] -= 0.125 * gamma1corr->get(hj, jj, kk);
                    if (j == k && hi == hl) G.matrix[h][ij][kl] -= 0.125 * gamma1corr->get(hi, ii, ll);
                    if (i == j && hk == hl) G.matrix[h][ij][kl] -= 0.125 * gamma1corr->get(hk, kk, ll);
                    if (k == l && hi == hj) G.matrix[h][ij][kl] -= 0.125 * gamma1corr->get(hi, ii, jj);
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Print
        if (print_ > 3) {
            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), 0,
                                   "TPDM <OO|OO>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);
        }

        // TPDM <OO|VV>
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,O]"), ID("[V,V]"), ID("[O,O]"), ID("[V,V]"), 0,
                               "TPDM <OO|VV>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int ab = 0; ab < G.params->coltot[h]; ++ab) {
                    int a = G.params->colorb[h][ab][0];
                    int b = G.params->colorb[h][ab][1];
                    int ha = G.params->rsym[a];
                    int hb = G.params->ssym[b];
                    int aa = a - G.params->roff[ha] + occpiA[ha];
                    int bb = b - G.params->soff[hb] + occpiA[hb];
                    if (i == j && ha == hb) G.matrix[h][ij][ab] -= 0.125 * gamma1corr->get(ha, aa, bb);
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Print
        if (print_ > 3) {
            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,O]"), ID("[V,V]"), ID("[O,O]"), ID("[V,V]"), 0,
                                   "TPDM <OO|VV>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);
        }

        // TPDM <OV|OV>
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), 0,
                               "TPDM <OV|OV>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ia = 0; ia < G.params->rowtot[h]; ++ia) {
                int i = G.params->roworb[h][ia][0];
                int a = G.params->roworb[h][ia][1];
                for (int jb = 0; jb < G.params->coltot[h]; ++jb) {
                    int j = G.params->colorb[h][jb][0];
                    int b = G.params->colorb[h][jb][1];

                    int ha = G.params->qsym[a];
                    int hb = G.params->ssym[b];
                    int aa = a - G.params->qoff[ha] + occpiA[ha];
                    int bb = b - G.params->soff[hb] + occpiA[hb];

                    if (i == j && ha == hb) {
                        if (wfn_type_ == "OMP2")
                            G.matrix[h][ia][jb] = 0.5 * gamma1corr->get(ha, aa, bb);
                        else
                            G.matrix[h][ia][jb] += 0.5 * gamma1corr->get(ha, aa, bb);
                    }
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Print
        if (print_ > 3) {
            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), 0,
                                   "TPDM <OV|OV>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);
        }

    }  // end if (reference_ == "RESTRICTED")

    else if (reference_ == "UNRESTRICTED") {
        // TPDM OOOO-Block
        // Alpha-Alpha spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), 0,
                               "TPDM <OO|OO>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int kl = 0; kl < G.params->coltot[h]; ++kl) {
                    int k = G.params->colorb[h][kl][0];
                    int l = G.params->colorb[h][kl][1];

                    int hi = G.params->psym[i];
                    int hj = G.params->qsym[j];
                    int hk = G.params->rsym[k];
                    int hl = G.params->ssym[l];

                    int ii = i - G.params->poff[hi];
                    int jj = j - G.params->qoff[hj];
                    int kk = k - G.params->roff[hk];
                    int ll = l - G.params->soff[hl];

                    if (i == k && hj == hl) G.matrix[h][ij][kl] += 0.25 * gamma1corrA->get(hj, jj, ll);
                    if (j == l && hi == hk) G.matrix[h][ij][kl] += 0.25 * gamma1corrA->get(hi, ii, kk);
                    if (i == l && hj == hk) G.matrix[h][ij][kl] -= 0.25 * gamma1corrA->get(hj, jj, kk);
                    if (j == k && hi == hl) G.matrix[h][ij][kl] -= 0.25 * gamma1corrA->get(hi, ii, ll);
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Beta-Beta spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[o,o]"), ID("[o,o]"), ID("[o,o]"), ID("[o,o]"), 0,
                               "TPDM <oo|oo>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int kl = 0; kl < G.params->coltot[h]; ++kl) {
                    int k = G.params->colorb[h][kl][0];
                    int l = G.params->colorb[h][kl][1];

                    int hi = G.params->psym[i];
                    int hj = G.params->qsym[j];
                    int hk = G.params->rsym[k];
                    int hl = G.params->ssym[l];

                    int ii = i - G.params->poff[hi];
                    int jj = j - G.params->qoff[hj];
                    int kk = k - G.params->roff[hk];
                    int ll = l - G.params->soff[hl];

                    if (i == k && hj == hl) G.matrix[h][ij][kl] += 0.25 * gamma1corrB->get(hj, jj, ll);
                    if (j == l && hi == hk) G.matrix[h][ij][kl] += 0.25 * gamma1corrB->get(hi, ii, kk);
                    if (i == l && hj == hk) G.matrix[h][ij][kl] -= 0.25 * gamma1corrB->get(hj, jj, kk);
                    if (j == k && hi == hl) G.matrix[h][ij][kl] -= 0.25 * gamma1corrB->get(hi, ii, ll);
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Alpha-Beta spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,o]"), ID("[O,o]"), ID("[O,o]"), ID("[O,o]"), 0,
                               "TPDM <Oo|Oo>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ij = 0; ij < G.params->rowtot[h]; ++ij) {
                int i = G.params->roworb[h][ij][0];
                int j = G.params->roworb[h][ij][1];
                for (int kl = 0; kl < G.params->coltot[h]; ++kl) {
                    int k = G.params->colorb[h][kl][0];
                    int l = G.params->colorb[h][kl][1];

                    int hi = G.params->psym[i];
                    int hj = G.params->qsym[j];
                    int hk = G.params->rsym[k];
                    int hl = G.params->ssym[l];

                    int ii = i - G.params->poff[hi];
                    int jj = j - G.params->qoff[hj];
                    int kk = k - G.params->roff[hk];
                    int ll = l - G.params->soff[hl];

                    if (i == k && hj == hl) G.matrix[h][ij][kl] += 0.25 * gamma1corrB->get(hj, jj, ll);
                    if (j == l && hi == hk) G.matrix[h][ij][kl] += 0.25 * gamma1corrA->get(hi, ii, kk);
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Print
        if (print_ > 3) {
            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), ID("[O,O]"), 0,
                                   "TPDM <OO|OO>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);

            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[o,o]"), ID("[o,o]"), ID("[o,o]"), ID("[o,o]"), 0,
                                   "TPDM <oo|oo>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);

            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,o]"), ID("[O,o]"), ID("[O,o]"), ID("[O,o]"), 0,
                                   "TPDM <Oo|Oo>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);
        }

        // TPDM <OV|OV>
        // Alpha-Alpha spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), 0,
                               "TPDM <OV|OV>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ia = 0; ia < G.params->rowtot[h]; ++ia) {
                int i = G.params->roworb[h][ia][0];
                int a = G.params->roworb[h][ia][1];
                for (int jb = 0; jb < G.params->coltot[h]; ++jb) {
                    int j = G.params->colorb[h][jb][0];
                    int b = G.params->colorb[h][jb][1];
                    int ha = G.params->qsym[a];
                    int hb = G.params->ssym[b];
                    int aa = a - G.params->qoff[ha] + occpiA[ha];
                    int bb = b - G.params->soff[hb] + occpiA[hb];
                    if (i == j && ha == hb) {
                        if (wfn_type_ == "OMP2")
                            G.matrix[h][ia][jb] = 0.25 * gamma1corrA->get(ha, aa, bb);
                        else
                            G.matrix[h][ia][jb] += 0.25 * gamma1corrA->get(ha, aa, bb);
                    }
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Beta-Beta spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[o,v]"), ID("[o,v]"), ID("[o,v]"), ID("[o,v]"), 0,
                               "TPDM <ov|ov>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ia = 0; ia < G.params->rowtot[h]; ++ia) {
                int i = G.params->roworb[h][ia][0];
                int a = G.params->roworb[h][ia][1];
                for (int jb = 0; jb < G.params->coltot[h]; ++jb) {
                    int j = G.params->colorb[h][jb][0];
                    int b = G.params->colorb[h][jb][1];
                    int ha = G.params->qsym[a];
                    int hb = G.params->ssym[b];
                    int aa = a - G.params->qoff[ha] + occpiB[ha];
                    int bb = b - G.params->soff[hb] + occpiB[hb];
                    if (i == j && ha == hb) {
                        if (wfn_type_ == "OMP2")
                            G.matrix[h][ia][jb] = 0.25 * gamma1corrB->get(ha, aa, bb);
                        else
                            G.matrix[h][ia][jb] += 0.25 * gamma1corrB->get(ha, aa, bb);
                    }
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Alpha-Beta spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,v]"), ID("[O,v]"), ID("[O,v]"), ID("[O,v]"), 0,
                               "TPDM <Ov|Ov>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ia = 0; ia < G.params->rowtot[h]; ++ia) {
                int i = G.params->roworb[h][ia][0];
                int a = G.params->roworb[h][ia][1];
                for (int jb = 0; jb < G.params->coltot[h]; ++jb) {
                    int j = G.params->colorb[h][jb][0];
                    int b = G.params->colorb[h][jb][1];
                    int ha = G.params->qsym[a];
                    int hb = G.params->ssym[b];
                    int aa = a - G.params->qoff[ha] + occpiB[ha];
                    int bb = b - G.params->soff[hb] + occpiB[hb];
                    if (i == j && ha == hb) {
                        if (wfn_type_ == "OMP2")
                            G.matrix[h][ia][jb] = 0.25 * gamma1corrB->get(ha, aa, bb);
                        else
                            G.matrix[h][ia][jb] += 0.25 * gamma1corrB->get(ha, aa, bb);
                    }
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Print
        if (print_ > 3) {
            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), 0,
                                   "TPDM <OV|OV>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);

            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[o,v]"), ID("[o,v]"), ID("[o,v]"), ID("[o,v]"), 0,
                                   "TPDM <ov|ov>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);

            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,v]"), ID("[O,v]"), ID("[O,v]"), ID("[O,v]"), 0,
                                   "TPDM <Ov|Ov>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);
        }

        // TPDM <Vo|Vo>
        // Alpha-Beta spin case
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[V,o]"), ID("[V,o]"), ID("[V,o]"), ID("[V,o]"), 0,
                               "TPDM <Vo|Vo>");
        for (int h = 0; h < nirrep_; ++h) {
            global_dpd_->buf4_mat_irrep_init(&G, h);
            if (wfn_type_ != "OMP2") global_dpd_->buf4_mat_irrep_rd(&G, h);
#pragma omp parallel for
            for (int ai = 0; ai < G.params->rowtot[h]; ++ai) {
                int a = G.params->roworb[h][ai][0];
                int i = G.params->roworb[h][ai][1];
                for (int bj = 0; bj < G.params->coltot[h]; ++bj) {
                    int b = G.params->colorb[h][bj][0];
                    int j = G.params->colorb[h][bj][1];
                    int ha = G.params->psym[a];
                    int hb = G.params->rsym[b];
                    int aa = a - G.params->poff[ha] + occpiA[ha];
                    int bb = b - G.params->roff[hb] + occpiA[hb];
                    if (i == j && ha == hb) {
                        if (wfn_type_ == "OMP2")
                            G.matrix[h][ai][bj] = 0.25 * gamma1corrA->get(ha, aa, bb);
                        else
                            G.matrix[h][ai][bj] += 0.25 * gamma1corrA->get(ha, aa, bb);
                    }
                }
            }
            global_dpd_->buf4_mat_irrep_wrt(&G, h);
            global_dpd_->buf4_mat_irrep_close(&G, h);
        }
        global_dpd_->buf4_close(&G);

        // Print
        if (print_ > 3) {
            global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[V,o]"), ID("[V,o]"), ID("[V,o]"), ID("[V,o]"), 0,
                                   "TPDM <Vo|Vo>");
            global_dpd_->buf4_print(&G, "outfile", 1);
            global_dpd_->buf4_close(&G);
        }

        // G_IABJ = -GIAJB so I do not need to OVVO block,
        //  however for proper contraction (to avoid construction of <OV||VV>)  in the GFock.cc I need it.
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), ID("[O,V]"), 0,
                               "TPDM <OV|OV>");
        global_dpd_->buf4_sort(&G, PSIF_OCC_DENSITY, pqsr, ID("[O,V]"), ID("[V,O]"), "TPDM <OV|VO>");
        global_dpd_->buf4_close(&G);
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,V]"), ID("[V,O]"), ID("[O,V]"), ID("[V,O]"), 0,
                               "TPDM <OV|VO>");
        global_dpd_->buf4_scm(&G, -1.0);
        global_dpd_->buf4_close(&G);

        /*
        dpd_buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[O,V]"), ID("[V,O]"),
                      ID("[O,V]"), ID("[V,O]"), 0, "TPDM <OV|VO>");
        dpd_buf4_print(&G, outfile, 1);
        dpd_buf4_close(&G);
        */

        // G_iabj = -Giajb so I do not need to ovvo block,
        //  however for proper contraction (to avoid construction of <ov||vv>)  in the GFock.cc I need it.
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[o,v]"), ID("[o,v]"), ID("[o,v]"), ID("[o,v]"), 0,
                               "TPDM <ov|ov>");
        global_dpd_->buf4_sort(&G, PSIF_OCC_DENSITY, pqsr, ID("[o,v]"), ID("[v,o]"), "TPDM <ov|vo>");
        global_dpd_->buf4_close(&G);
        global_dpd_->buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[o,v]"), ID("[v,o]"), ID("[o,v]"), ID("[v,o]"), 0,
                               "TPDM <ov|vo>");
        global_dpd_->buf4_scm(&G, -1.0);
        global_dpd_->buf4_close(&G);

        /*
        dpd_buf4_init(&G, PSIF_OCC_DENSITY, 0, ID("[o,v]"), ID("[v,o]"),
                      ID("[o,v]"), ID("[v,o]"), 0, "TPDM <ov|vo>");
        dpd_buf4_print(&G, outfile, 1);
        dpd_buf4_close(&G);
        */

    }  // end if (reference_ == "UNRESTRICTED")
    psio_->close(PSIF_OCC_DENSITY, 1);
}
}
}  // End Namespaces
